Digital indicating device

ABSTRACT

A reflecting element has at least one curved surface having a first plane of symmetry and being operative for reflecting incident light. A varying element is provided for varying the character of the reflector light and has a second symmetry paralleling the first plane. The elements are relatively moveable between an operative position and an inoperative position in which the varying element respectively varies and does not vary the character of light reflected by the reflecting element. An arrangement is provided for effecting such relative movement of the elements.

Unie States Patent 1 Gl'tittli DIGITAL INDICATING DEVICE [75] Inventor:Hansheinrich Gliittli, Kusnacht,

swiili lldw a [73] Assignee: Pneumotech AG, Fallanden,

Switzerland [22] Filed: Apr. 12, 1972 [21] Appl. No.: 243,203

[30] Foreign Application Priority Data 3,447,862 6/ 1969 Elpem 350/2663,309,665 3/1967 Kohl 350/6 3,625,598 12/1971 Brown 350/285 3,479,75911/1969 Lattis et 40/1065] 1,272,811 7/1918 Jones 350/301 PrimaryExaminerDavid Schonberg Assistant Examiner-Michael J. TokarAttorney-Michael S. Striker [57] ABSTRACT A reflecting element has atleast one curved surface having a first plane of symmetry and beingoperative for reflecting incident light. A varying element is providedfor varying the character of the reflector light and has a secondsymmetry paralleling the first plane. The elements are relativelymoveable between an operative position and an inoperative position inwhich the varying element respectively varies and does not vary thecharacter of light reflected by the reflecting element. An arrangementis provided for effecting such relative movement of the elements.

15 Claims, 7 Drawing Figures DIGITAL INDICATING DEVICE BACKGROUND OF THEINVENTION The present invention relates generally to an indicatordevice, and more particularly to a digital indicator device.

Indicator devices of the general type here under discussion are alreadyknown, their purpose being to provide an indication by changing thecharacter of reflected light. In one prior-art construction there isprovided a light-reflecting element which is conflgurated as arod-shaped member having a free end which is rounded and with thisrod-shaped member being mounted in the symmetry axis of a reflectorwhose reflecting surface is configurated as a symmetrical surface ofrotation. Depending upon the binary condition to be indicated by thedevice, the rod-shaped member is pushed into the effective reflectingregion of the reflector, or withdrawn therefrom.

The entire surface of the rod-shaped member, including its rounded endface, is provided with a reflecting or phosphorizing coating. Thisvmeans that if the rodshaped member is withdrawn to what should normallybe an inoperative position in which it does not cooperate with thereflector and thus does not vary the character of light reflected by thelatter, the coated free end face of the rod-shaped member continuesunder all circumstances to be visible when the device is viewed. This isa significant disadvantage because it introduces a condition ofuncertainty asto whether a signal is being indicated by varying of thelight reflected by the reflector, or not. The difficulty results fromthe fact that even if a signal to be indicated does not exist, a hastyglance of a viewer or disadvantageous ambient lighting conditions maylead due to the continuing visibility of the free end face of therod-shaped memberto the assumption that such a signal is actually beingindicated.

In addition, this prior-art device has the disadvantage that the viewingside of the device, where the character of the reflected light is viewedto obtain information as to whether-or not the device indicates thepresence or absence of a signal, can only be of circular configurationdue to the fact that both the rod-shaped member and the reflector are ofcircular cross-section.

SUMMARY OF THE INVENTION Accordingly, it is a general'object of thepresent invention to provide adevice of the character here underdiscussion which avoids the disadvantages of the prior art.

More particularly it is an object of the invention to provide such adevice which will afford a reliable and non-ambiguous indication-underall circumstances.

Another object of the invention is to provide such a device in which theviewing side can be of other-thancircular outline.

In pursuance of these objects, and of others which will become apparenthereafter, one feature of the invention resides, in a device of thecharacter described, particularly in a digital indicator, which brieflystated comprises a reflecting element provided with at least one curvedsurface and having a first plane of symmetry and being operative forreflecting incident light. A varying element is provided for varying thecharacter of light reflected by the reflecting element and has a secondplane of symmetry paralleling the first plane.

The elements are relatively movable between at least one operativeposition and an inoperative position in which the varying elementrespectively varies and does not vary the character of light reflectedby the reflecting element. Moving means is provided for effectingrelative movement of the elements between the aforementioned positionsthereof.

The varying element may have planar or curved surfaces, and itsprojection onto the viewing plane should at least approach zero. Thereflecting element, on the other hand, has a curved or spherical surfacewhose axis of symmetry is in parallel with the plane or axis of symmetryof the varying element itself. By resorting to this construction nolight-reflecting surface portion of the varying element remains visiblewhen a signal is not being indicated. This prevents to all intents andpurposes a mistaken reading of anindication provided by the deviceaccording to the present invention. Moreover, the device can have aread-out side or viewing side which is of non-circular outline, forinstance quadratic or rectangular as is desirable in many applica tions.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING ing movement of the movable element;and

FIG. 5 is a view analogous to FIG. 1 but illustrating an additionalembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly theembodiment in FIGS. 1 and 2 it will be seen that reference numeral 1designates a reflecting element which in the particular embodimentillustrated has two part-cylindrical reflecting surface portions 1a andlb which are separated by an axially extending slot, and whose cylinderaxis extend in parallelism but are transversely spaced from one another.A varying element 3 in form of a plate, strip or the like which is flatand planar and which can be moved upand-down in the slot 2 as indicatedby the arrow in FIG. 1. At opposite axial ends of the slot 2 the element3 is guided in guide slots 5 provided for this purpose in a lateralframe portion 4 which bounds the reflector I and is illustrated onlydiagrammatically.

It should be noted that the plane of symmetry of the element 3 is normalto the viewing plane of the device which is identical with the planeof'the drawing in the tion provided by the element one would normallylook downwardly onto the device as in FIG. 2.

The element 3 is moved from the illustrated inoperative position of FIG.1 in upward direction (see the arrow of FIG. I) to provide anindication, that is to vary the character of light reflected by thesurface portions Ia and lb, and for this purpose there is provided inthe embodiment of FIGS. I and 2 a bellows member 6 which flexes upwardlywhen pressure is exerted from below and permits the element 3 to moveupwardly in the slot 2. Of course, other means can also be provided forthis purpose, such as pneumatic cylinders, hydraulic cylinders,electromagnetic means or the like. The member 6 may for instance be madeof spring steel or the like and will inherently tend to restore theelement 3 to the position shown in FIG. I when upward pressure on themember 6 is relaxed.

The side or lateral surfaces of the element 3 may be coated with astrongly light-reflecting paint or the like, for instance aphosporescent paint, but the entire member 3 may inherently be coloredwith a phosphorescing or light-reflectant paint so that it is luminous,for instance by being provided in form of a transparent foil or sheetwhich is tinted with the desired color.

When the element 6 is activated, for instance by subjecting it frombelow to the action of a suitable pressure.

fluid, it will effect upward movement of the element 3 in the directionof the arrow in FIG. 1, thereby causing the lateral surfaces of theelement 3 to move into'the effective region of the reflector I. If thecurvature of the reflector l is appropriately selected, which is amatter known to those skilled in the art, the entire viewing plane willthen appear to be illuminated with a light which is illustrated in FIG.I. The entire effective surface of the element 3 thus disappears out ofthe effective range of the reflector I, and no residual indicatingeffect exists as was the case in the aforementioned prior-artconstruction. It should be noted that the upper edge of the element 3,which is exposed in the slot 2, is not coated with the luminescent paintand, even if the 'element 3 is inherently tinted to be luminescent, thiswould not be of any significance because due to its entire withdrawalfrom the effective region of the reflector I, insufficient light wouldenter into the element 3 to be able to cause the color tinting of thelatter to provide a modified-light read-out indication in the viewingplane of the device. Thus, it may be said that in the rest position asshown in FIG. 1 the projection of the element 3 into the viewing planeis equal to or approaches zero, meaning that the element 3 in its restposition does not influence at all the appearance of light reflected bythe reflector I, as it is viewed in the viewing plane.

FIG. la shows that it is also possible to provide the opposite surfacesof the element 3 with two different layers 3' and 3" of luminescent ofphosphorescent paint.

FIG. lb shows that two or more (two shown) of the elements 3 may beprovided, which can be each independently moved to operative and restposition by the diagrammatically illustrated moving means MM which againmay be of any of the various types mentioned earlier. The elements 3, 3in FIG. l b extend in parallelism with one another and-it will beappreciated that the surfaces of one of these elements may be coatedwith one paint and the surfaces of the other with a different paint, orthat both of the elements may be tinted, each with a'different color. Insuch a construction selective activation of either or both of theelements 3 provides a further read-out signal condition. For instance,the one element 3 may be tinted or be provided with a coating of redcolor, and the other element may be provided with a green color.

The reflector I may be of metal or synthetic plastic material; in termsof manufacture it is particularly advantageous if it is syntheticplastic material which is mirrored, that is which has metallic materialdeposited on it in order to provide a mirror reflecting surface. Theelement 3 may also be of snythetic plastic material, advantageously of atransparent synthetic plastic material which may be tinted withfluorescent or otherwise luminescent paint or dye. Such materials aswell as paints and dyes for this purpose are too well known to requiredetailed discussion and do not in any case form a part of the-invention.

The embodiment illustrated in FIG. 3 resembles that of FIG. 1, andcertain components have been omitted for the sake of clarity. Likereference numerals designate like elements as in FIG. 1. The embodimentof FIG. 3 differs from that of FIG. 1 in that a more even illuminationof the viewing plane is obtained and a better indication by light isachieved, by having a plate or cap member 7 located at or substantiallyin the viewing plane and provided with grooves, concentric rings, orotherwise light dispersing formations in form of a single or severalrasters. Of course, the member 7 must be transparent or at leasttranslucent and it is advantageous if grooves are provided which extendin parallelmember 7 may also be of synthetic plastic material.

The embodiment in FIG. 4 is exemplary of an arrangement for effectingmovement of the member 3 between its operative and inoperativepositions. In this embodiment there is provided a diagrammaticallyillustrated cylinder 8 in which a piston is displaceable, being providedwith a piston rod which carries an abutment 9. The abutment 9 is locatedexteriorly of the cylinder 8 and is connected directly with the element3. An expansion spring It) bears upon the abutment 9 and on the exteriorside of the reflector I which is shown only fragmentarily in thisFigure. When the piston 8a is moved upwardly under the influence of asuitable pressure force F as indicated by the arrow in FIG. 4, thespring 10 yields and the element 3 moves into the reflector 1. When thepressure P is released, however, the member 3 is withdrawn to theposition shown in FIG. 4 by the expansion of the spring 10. It will,however, be appreciated that if for instance the element 6 of FIG. I isutilized and is of such type that it will resiliently restore theelement 3 to the rest position shown in FIG. I, the spring I0 may beomitted. Evidently, substan tially lower activating forces are requiredthan in FIG.

4 in such a case, to place the member 3 from the rest possible toconfigurate the varying element (designated heretofore with referencenumeral 3) as a cylindrically configurated element 11. Of course, otherconfiguraf. tions beside the cylinder configuration can be chosen; Itmust however, always be kept in mind that the effec- -tive surface ofthe element ll will be normal with respect to the viewing plane. Puttingthis differently it can be said that the surface of the element 11 (or 3in the preceding embodiment) which is projected into the viewing planemust be as small as possible and should preferably approach zero.

In FIG. 5 the reflector is designated with reference numeral 12 and hasa reflecting surface which is configurated as a surface of rotation,having an axis of symmetry which extends in parallelism with thelongitudinal axis of the cylindrical varying element 1 1. ln theillustrated embodiment the two axis are coincident and the element 11concentrically surrounds the reflector 12. A housing 113 is provided,surrounding the device and being transparent for viewing purposes atleast in the region of the viewing plane, as indicated in FIG. 5. It is,however, advantageous if the transparent portion of the housing 13extends further downwardly than shown so that it is possible to read anindication provided by the device even if the device is viewed under arelatively flat angle.

It will be understood that the element 11, which is movable by any ofthe previously mentioned means with respect to the element 12, couldalso be made stationary with the element 12 being mounted so that it canbe moved with reference to the element 11. When the reflector 12 wouldthen be raised, that is in the direction towards the viewing plane, theeffective surface of the element 11 would become covered to preventmodification of the character of the reflected light, whereas a loweringof the reflector l2 away from the viewing plane would make the effectivesurface of the element 11 become fully operative.

This reversion of the stationary and movable elements is of coursepossible in the other embodiments also.

It will be appreciated that a particular advantage of the constructionaccording to the present invention resides in the fact that it requiresno active optical components at all, but is based exclusively onitheprinciple of varying the'character of incident light, that is lightwhich impinges onto the reflector of the device. This means that thedevice will automatically accommodate itself to the ambient brightnessexisting at any given moment. The advantage of this will be appreciatedwhen it is considered that a significant disadvantage of the presentinvention.

a useful application in other types of constructions differing from thetypes described above. 7

While the invention has been illustrated and de-' scribed as embodied ina digital indicating device, it is not intended to be limited to thedetails shown, since various modifications and structural changes may bemade without departing in any way from the spirit of Without furtheranalysis, the foregoing will so fully reveal the gist of the presentinvention that others can by applying current knowledge readily adapt itfor various applications without omitting features that, from thestandpoint of prior art, fairly constitute essential characteristics ofthe generic or specific aspects of this invention and, therefore, suchadaptations should and are intended to be comprehended withinthe meaningand range of equivalence of the following claims. I

What is claimed as new and desired to be protected be Letters Patent isset forth. in the appended claims.

1. A device of the character described, particularly a digitalindicator, comprising a reflecting element provided with a curvedreflecting surface bounding an opening through which incident light isadmitted to be reflected by said reflecting surface, said reflectingsurface having a first plane of symmetry; a varying element for varyingthe character of light reflected by said reflecting element and having asecond plane of symmetry paralleling said first plane, said elementsbeing relatively movable between at least one operative position and aninoperative position in which said varying element is closer to and'farther spaced from said opening and respectively varies and does notvary the character of light admitted through said opening and reflectedby said reflecting element; and moving means for effecting relativemovement of said elements between said positions thereof.

2. A device as defined in claim 15, said reflecting element having anindicating plane from which it is viewed to determine the character ofreflected light; and wherein said varying element is so constructed thatits projection onto such indicating plane approaches zero.

3. A device as defined in claim 15, wherein said varying elementselectively reflects light.

4. A device as defined in claim 15, wherein said varying elementselectively absorbs light.

5. A device as defined in claim 15, said varying element having at leastone exposed surface; and further comprisinga coating of luminescentmaterial.

6. A device as defined in claim 15, said varying element beingluminescent.

' 7. A device as defined in claim, 15, said curved surface comprisingtwo part-cylindrical surface portions having transversely spacedparallel cylinder axes.

8. A device as defined in claim 15, said reflecting element beingbox-shaped and being of right-angled crosssection in direction normal tothe direction of relative movement of said elements.

9. A device as defined in claim 15, said reflecting element having anindicating plane from which it is to be viewed to determine thecharacter of the reflected light; and further comprising alight-diffusing member provided on said reflecting element in the regionof said viewing plane. I

10. A device as defined in claim 15, wherein said varying element ismovable with reference to said re flecting element between saidoperative and inoperative positions.

reference to said reflecting element; and wherein-said;

moving means is operative for moving said varying elelmentsindependently of one another, each between s'aid operative andinoperative positions.

12. A device of the character described, particularly a digitalindicator, comprising a reflecting element provided with at least onecurved surface configurated as a surface of revolution having an axis ofsymmetry and being operative for reflecting incident light; a varyingelement for varying the character of light reflected by said reflectingelement, said varying element being configurated as a cylindersurrounding said reflecting element and having a longitudinal axiscoinciding with said axis of symmetry, said cylinder having an open endfor viewing and for admission of light, said elements being relativelymovable between at least one operative position and an inoperativeposition in which said varying element respectively varies and does notvary the character of light reflected by said reflecting element; andmoving means for effecting relative movement of said elements betweensaid positions thereof.

13. A device as defined in claim 16, wherein said reflecting element ismovable with reference to said varying element between said operativeand inoperative positions, longitudinally of said axis of symmetry. "1

14. A device as claimed in claim 15, said moving means comprising aresiliently flexible member operatively associated with one of saidelements, said mem-.

her being flexiblefor enabling movement of said one element to saidoperative position but inherently biasing said one element to saidinoperative position.

15. A device of the character described, particularly a digitalindicator, comprising a reflecting element provided with at least onecurved surface having a first plane of symmetry and operative forreflecting incident light, the curvature of said surface being such thatthe intensity of the reflected light is substantially the same in alldirections; a varying element for varying the character of lightreflected by said reflecting element and having a second plane ofsymmetry paralleling said first plane, said elements being relativelymovable between at least one operative position and an inoperativeposition in which said varying element respectively varies and does notvary the character of light reflected by said reflecting element; andmoving means for effecting relative movement of said elements betweensaid positions thereof.

1. A device of the character described, particularly a digitalindicator, comprising a reflecting element provided with a curvedreflecting surface bounding an opening through which incident light isadmitted to be reflected by said reflecting surface, said reflectingsurface having a first plane of symmetry; a varying element for varyingthe character of light reflected by said reflecting element and having asecond plane of symmetry paralleling said first plane, said elementsbeing relatively movable betweEn at least one operative position and aninoperative position in which said varying element is closer to andfarther spaced from said opening and respectively varies and does notvary the character of light admitted through said opening and reflectedby said reflecting element; and moving means for effecting relativemovement of said elements between said positions thereof.
 2. A device asdefined in claim 15, said reflecting element having an indicating planefrom which it is viewed to determine the character of reflected light;and wherein said varying element is so constructed that its projectiononto such indicating plane approaches zero.
 3. A device as defined inclaim 15, wherein said varying element selectively reflects light.
 4. Adevice as defined in claim 15, wherein said varying element selectivelyabsorbs light.
 5. A device as defined in claim 15, said varying elementhaving at least one exposed surface; and further comprising a coating ofluminescent material.
 6. A device as defined in claim 15, said varyingelement being luminescent.
 7. A device as defined in claim 15, saidcurved surface comprising two part-cylindrical surface portions havingtransversely spaced parallel cylinder axes.
 8. A device as defined inclaim 15, said reflecting element being box-shaped and being ofright-angled cross-section in direction normal to the direction ofrelative movement of said elements.
 9. A device as defined in claim 15,said reflecting element having an indicating plane from which it is tobe viewed to determine the character of the reflected light; and furthercomprising a light-diffusing member provided on said reflecting elementin the region of said viewing plane.
 10. A device as defined in claim15, wherein said varying element is movable with reference to saidreflecting element between said operative and inoperative positions. 11.A device as defined in claim 15; further comprising at least oneadditional varying element, both of said varying elements being planarand located in parallel planes with freedom of independent movement withreference to said reflecting element; and wherein said moving means isoperative for moving said varying elements independently of one another,each between said operative and inoperative positions.
 12. A device ofthe character described, particularly a digital indicator, comprising areflecting element provided with at least one curved surfaceconfigurated as a surface of revolution having an axis of symmetry andbeing operative for reflecting incident light; a varying element forvarying the character of light reflected by said reflecting element,said varying element being configurated as a cylinder surrounding saidreflecting element and having a longitudinal axis coinciding with saidaxis of symmetry, said cylinder having an open end for viewing and foradmission of light, said elements being relatively movable between atleast one operative position and an inoperative position in which saidvarying element respectively varies and does not vary the character oflight reflected by said reflecting element; and moving means foreffecting relative movement of said elements between said positionsthereof.
 13. A device as defined in claim 16, wherein said reflectingelement is movable with reference to said varying element between saidoperative and inoperative positions, longitudinally of said axis ofsymmetry.
 14. A device as defined in claim 15, said moving meanscomprising a resiliently flexible member operatively associated with oneof said elements, said member being flexible for enabling movement ofsaid one element to said operative position but inherently biasing saidone element to said inoperative position.
 15. A device of the characterdescribed, particularly a digital indicator, comprising a reflectingelement provided with at least one curved surface having a first planeof symmetry and operative for reflecting incident light, the curvatureof said Surface being such that the intensity of the reflected light issubstantially the same in all directions; a varying element for varyingthe character of light reflected by said reflecting element and having asecond plane of symmetry paralleling said first plane, said elementsbeing relatively movable between at least one operative position and aninoperative position in which said varying element respectively variesand does not vary the character of light reflected by said reflectingelement; and moving means for effecting relative movement of saidelements between said positions thereof.